1. Field of Invention
The present invention relates broadly to incineration of wastes and more particularly to fluidized bed incineration of waste containing phosphorus using a bed material which negates the previously existing harmful effects of phosphorus.
2. Prior Art
Special purpose fluidized bed apparatus and methods are known. For example, U.S. Pat. Nos. 3,834,326; 4,060,041 and 4,075,953 respectively deal with incineration of solid wastes, principally those obtained from saw mills and the like. In particular, the last two mentioned U.S. Patents deal with customizing the bed material of the fluidized bed to comprise olivine whereby certain improved results may be obtained.
Furthermore, the unique problems incident to removal of sulfur from fuels using lime are treated by U.S. Pat. Nos. 3,625,164 and 3,807,090.
Notwithstanding the foregoing, until the present invention no solution has been proposed for negating the deleterious side effects encountered in conventional fluidized bed incineration of wastes containing phosphorus, i.e. (a) formation of highly corrosive phosphoric acid within the fluidized bed vessel, (b) formation of a hard glass-like slag or scale material which tends to adhere to the walls of gas flow passageways and heat transfer surfaces within the apparatus causing a marked reduction in efficiency, and (c) formation of liquid by-products which adhere to the particles of conventional bed materials destroying the needed fluidization qualities.
The deleterious side effects limit the effectiveness of certain exhaust gas cleaning equipment due to corrosion or plugging which can result in the release of harmful materials to the atmosphere.